Application value of the spectral CT imaging in the qualitative evaluation of metastatic lymph nodes of differently differentiated esophageal cancer

ObjectiveTo explore the application value of spectral CT imaging in the qualitative evaluation of metastatic lymph nodes of differently differentiated esophageal cancer.

MethodsThe clinical data of 48 patients with esophageal squamous cell carcinoma confirmed by endoscopic pathology were retrospectively analyzed.All cases were detected using spectral CT chest plain scan and dual-phase enhanced scan before surgery.The short diameter of mediastinal lymph nodes, CT value at 70 keV arterial and iodine concentration in arterial and venous phases were measured, the normalized iodine concentration was calculated, and which was compared with the postoperative pathological results.

ResultsAmong the 48 patients with esophageal squamous cell carcinoma, 32 cases with lymph node metastasis and 16 cases without lymph node metastasis were confirmed by operation and pathology.The postoperative pathological results showed that 79 metastatic lymph nodes were found(including 14 highly differentiated squamous cell carcinoma metastatic lymph nodes, 27 moderately differentiated squamous cell carcinoma metastatic lymph nodes and 38 poorly differentiated squamous cell carcinoma metastatic lymph nodes), and there were 32 non-metastatic lymph nodes.There was no statistical significance in the diagnosis of lymph node metastasis between spectral CT imaging and pathological results after surgery(P>0.05).The short diameter, CT_{70 keV} and arterial phase hormalized iodine concentration in highly and moderately differentiated esophageal squamous cell carcinoma metastatic lymph nodes were higher than those in non-metastatic lymph nodes(P < 0.05 to P < 0.01).The short diameter, CT_{70 keV} and arterial phase hormalized iodine concentration in pooryly differentiated esophageal squamous cell carcinoma metastatic lymph nodes were higher than those in non-metastatic lymph nodes(P < 0.05 to P < 0.01).The ROC curve analysis showed that the sensitivity and specificity of the combined of CT_{70 keV}, normalized iodine concentration and spectral curve slope in arterial phase in the diagnosis of metastatic lymph node of esophageal cancer were 86.1% and 87.5%, respectively.

ConclusionsThe spectral CT imaging has important value in qualitative valuating the lymph nodes of differently differentiated esophageal cancer.It is helpful for N staging, clinical diagnosis and choice of treatment option of esophageal cancer.